Press Ignores Study that Could Reduce Mercury Use

by Howard Fienberg
april 30, 2001

Environmental activists have campaigned against mercury-based hospital instruments, citing the possibility of dangerous mercury pollution from either instrument breakage or waste incineration. More and more localities and retail chains are banning or phasing out mercury-based thermometers and blood pressure measurement devices (“Senate Panel OK’s Anti-mercury Bill,” Sacramento Bee, Apr. 3). Defenders of the instruments have had one major fallback position: Accuracy and reliability can only be achieved with mercury. So a new study refuting that position should have been big news.

Mercury-based sphygmomanometers (the technical term for blood-pressure measurement devices) have long been the medical gold standard. Non-mercury (or aneroid) sphygmomanometers have been criticized as much less accurate (primarily because their complex mechanical parts are prone to failure). In February, an editorial in Hypertension: The Journal of the American Heart Association warned that the newer aneroid devices, while lighter and more convenient, were unreliable. But Dr. Vincent Canzanello reported in the March Archives of Internal Medicine (AIM) that hospitals need no longer worry about their aneroid devices.

Canzanello investigated the accuracy of a sample of aneroid sphygmomanometers and found them suitably accurate when tested against the mercury standard. The main problem he identified was in upkeep. Following a proper maintenance schedule was the key factor in sustaining accurate aneroid measurements.

While further studies will probably be needed, the AIM study should have quickened many an environmental journalist’s pulse. The study deserved press attention and a Nexis search found that it got it. Unfortunately, it came only from Medical Industry Today (Mar. 13) and a short piece in Reuters (Mar. 11).

Howard Fienberg is a research analyst with the nonpartisan Statistical Assessment Service, a non-profit organization devoted to the accurate use of scientific and social research in public policy debate.

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